org.jboss.remoting3.remote.MessageReader Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
/*
* JBoss, Home of Professional Open Source.
* Copyright 2017 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.remoting3.remote;
import static org.jboss.remoting3._private.Messages.conn;
import static org.xnio.IoUtils.safeClose;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayDeque;
import java.util.Iterator;
import org.xnio.Buffers;
import org.xnio.ByteBufferPool;
import org.xnio.ChannelListener;
import org.xnio.Pooled;
import org.xnio.conduits.ConduitStreamSourceChannel;
/**
* @author David M. Lloyd
*/
final class MessageReader {
private final ConduitStreamSourceChannel sourceChannel;
private final ArrayDeque queue = new ArrayDeque<>();
private final Object lock;
private final ByteBuffer[] array = new ByteBuffer[16];
static final Pooled EOF_MARKER = Buffers.emptyPooledByteBuffer();
MessageReader(final ConduitStreamSourceChannel sourceChannel, final Object lock) {
this.sourceChannel = sourceChannel;
this.lock = lock;
}
ConduitStreamSourceChannel getSourceChannel() {
return sourceChannel;
}
Pooled getMessage() throws IOException {
synchronized (lock) {
for (;;) {
ByteBuffer first = queue.peekFirst();
if (first != null) {
if (first.remaining() >= 4) {
int size = first.getInt(first.position());
if (remaining(size + 4)) {
ByteBuffer message;
if (ByteBufferPool.MEDIUM_SIZE >= size) {
message = ByteBufferPool.MEDIUM_HEAP.allocate();
} else if (ByteBufferPool.LARGE_SIZE >= size) {
message = ByteBufferPool.LARGE_HEAP.allocate();
} else {
message = ByteBuffer.allocate(size);
}
first.getInt();
int cnt = 0;
while (cnt < size) {
cnt += Buffers.copy(size - cnt, message, first);
if (! first.hasRemaining()) {
ByteBufferPool.free(first);
queue.pollFirst();
first = queue.peekFirst();
}
}
message.flip();
if (first != null && first.position() + 4 > first.limit()) {
// compact & reflip just to make sure there's space for next time
first.compact();
first.flip();
}
conn.tracef("Received message %s", message);
return Buffers.globalPooledWrapper(message);
} else {
if (conn.isTraceEnabled()) {
conn.tracef("Not enough buffered bytes for message of size %d+4 (%s)", Integer.valueOf(size), first);
}
}
} else {
if (queue.peekLast() == first) {
// ready for re-filling
first.compact().flip();
} else {
// first can never be full enough; we have to copy a few bytes out of the next one
first.compact();
try {
final Iterator iterator = queue.iterator();
iterator.next(); // skip first
assert iterator.hasNext(); // at least one more buffer is present because last != first
do {
final ByteBuffer next = iterator.next();
if (next.remaining() > 4) {
first.putInt(next.getInt());
} else {
Buffers.copy(first, next);
iterator.remove(); //we have emptied the buffer so we remove it
}
} while (first.position() < 4 && iterator.hasNext());
if(first.position() >= 4) {
//we have enough to read the size, retry rather than attempting to read from the channel
continue;
}
} finally {
first.flip();
}
}
}
} else {
conn.trace("No buffers in queue for message header");
}
ByteBuffer[] b = array;
ByteBuffer last = queue.pollLast();
if (last != null) {
last.compact();
b[0] = last;
ByteBufferPool.MEDIUM_DIRECT.allocate(b, 1);
conn.tracef("Compacted existing buffer %s", last);
} else {
ByteBufferPool.MEDIUM_DIRECT.allocate(b, 0);
conn.tracef("Allocated fresh buffers");
}
try {
long res = sourceChannel.read(b);
if (res == -1) {
conn.trace("Received EOF");
return EOF_MARKER;
}
if (res == 0) {
conn.trace("No read bytes available");
return null;
}
if (conn.isTraceEnabled()) {
conn.tracef("Received %d bytes", Long.valueOf(res));
}
} finally {
for (int i = 0; i < b.length; i++) {
final ByteBuffer buffer = b[i];
if (buffer.position() > 0) {
buffer.flip();
queue.addLast(buffer);
} else {
ByteBufferPool.free(buffer);
}
b[i] = null;
}
}
}
}
}
private boolean remaining(int cnt) {
int rem = 0;
for (ByteBuffer buffer : queue) {
rem += buffer.remaining();
if (rem >= cnt) return true;
}
return false;
}
public void close() {
synchronized (lock) {
safeClose(sourceChannel);
ByteBuffer buffer;
while ((buffer = queue.pollFirst()) != null) {
ByteBufferPool.free(buffer);
}
}
}
public void setReadListener(final ChannelListener readListener) {
synchronized (lock) {
sourceChannel.setReadListener(readListener);
}
}
public void suspendReads() {
synchronized (lock) {
getSourceChannel().suspendReads();
}
}
public void resumeReads() {
synchronized (lock) {
getSourceChannel().resumeReads();
}
}
public void wakeupReads() {
synchronized (lock) {
getSourceChannel().wakeupReads();
}
}
public void shutdownReads() throws IOException {
synchronized (lock) {
getSourceChannel().shutdownReads();
}
}
}